Insufficient catalyst utilization, limited mass transport, and high ohmic resistance of the conventional membrane electrode assembly (MEA) lead to significant performance losses of proton exchange membrane water electrolysis (PEMWE). Herein we propose a novel ordered MEA based on anode with a 3D membrane/catalytic layer (CL) interface and gradient tapered arrays by the nanoimprinting method, confirmed by energy dispersive spectroscopy. Benefiting from the maximized triple-phase interface, rapid mass transport, and gradient CL by overall design, such an ordered structure with Ir loading of 0.2 mg cm-2 not only greatly increases the electrochemical active area by 4.2 times but also decreases the overpotentials of both mass transport and ohmic polarization by 13.9% and 8.7%, respectively, compared with conventional MEA with an Ir loading of 2 mg cm-2, thus ensuring a superior performance (1.801 V at 2 A cm-2) and good stability. This work provides a new strategy of designing MEA for high-performance PEMWE.
Keywords: 3D interface structure; gradient catalytic layer; low Ir loading; proton exchange membrane water electrolysis; tapered arrays structure.